And the changes worked wonders as Posh delivered a superb second-half showing to reach the last 16 of a competition which has a Wembley final as a prize.
There were some excellent marks for the players and the manager.
Ratings key: 10-Perfect, 9-Outstanding, 8-Very Good, 7-Good, 6-Okay, 5-Poor, 4-Very Poor, 3-Drreadful.
DAN GYOLLAI: A couple of decent saves in the first half and hardly tested after the break, until a late tip over the crossbar 7.
NIALL MASON: The captain for the night gave a solid defensive performance as one of three centre-backs. Joined in attacks when he could 7.
RONNIE EDWARDS: The teenager oozes class and the middle of the back three suits his passing ability and his skill at reading the game. Untroubled throughout 8.
FRAZER BLAKE-TRACY: A good comeback after his struggles at Pompey. Suits the left centre-back role with his strength and power. Did well against Ukranian international Yarmolenko 7.